My 5-year-old son put his hand through the playroom window the other day.

He ran through the kitchen, a bright blur of blonde hair and dimples, before I heard the sickening sound of shattered glass. Miraculously, he wasn’t hurt. I looked him over from head to toe, swept up the shards, and taped cardboard over the hole in the window before stress-eating an entire row of Oreo cookies.

Had my first child done this at that age, I would have been a basket case; but this is my second kid, and I’ve been hardened by years of chaos. Everything is different the second time around — it’s less stressful, because I know what I’m doing (I think?!), but also bittersweet, because I know how fast time zips by. I’m not even sure what I’ve been doing the past few years, or when my kids all learned how to use the toilet, but I’m going to go ahead and take full credit for all of it.

My younger son is an introvert. I often find him playing alone in his closet or under his bed, hiding treasures like tiny pieces of cardboard or marbles in hard-to-find places. He chatters quietly to himself. He’s shy, clumsy, and yet athletic. He’s dry and quirky; so different and yet so similar to the rest of the family. He is a walking contradiction with dimples.

Each of my children are equally special to me, but this one holds a piece of my heart that makes it extra-hard for me to step back and let him grow up.

He started Kindergarten a few weeks ago, and I steeled myself for all the emotions that accompany putting a tiny kid on a big bus and watching it drive away. I found myself endlessly grateful for his big brother, who is in third grade and can make sure he doesn’t wander into oncoming traffic, get lost in the school hallways, or any of my other irrational concerns.

My internal dialogue is different this time. He seems tinier than I remember his brother being at that age, more innocent and in need of my protection. Those feelings, of course, are all skewed by the fact that he’s simply my second child.

Every morning, as I stand in the kitchen with a cup of coffee watching them wait for the school bus to arrive, I experience the following thoughts:

How can such a little guy carry such a big backpack?

HE IS SO TINY.

What if he misses me while he’s at school and gets really sad?

What if the older kids are mean to him?

Will he eat his lunch?

While the actual act of sending him to school may be tough, dealing with everything else is easier. Since I’ve been through this once already, I am armed with the knowledge that I am a TERRIBLE room mom — no, really, I’m the worst — and at best, I am a subpar volunteer. I don’t feel compelled to sign up for things that I know I’m not good at. I don’t pretend to be a different kind of mom than the one that I am.

At orientation, I told his teacher that I don’t really like children aside from my own, and sometimes I don’t even like them … but I would be happy to help her in any way I can. Ways that don’t necessarily involve, you know, children. Her eyes grew wide before she started laughing, because she recognized that I’m a damn good mom. One who knows her limits and owns who she is.

So how does it really feel to send my second child off to kindergarten? I pondered that question as I peeked in on my little blonde boy, sitting happily at his desk.

Harmony Hobbs is a freelance writer who navigates the waters of motherhood without any grace or finesse whatsoever. She began her blog (Modern Mommy Madness) because writing costs zero dollars and therapy costs a lot of dollars, and has continued to self-medicate by writing down all the things that she can't say out loud. Harmony is a fan of coffee, wine, and very sturdy undergarments, and can be found on Instagram, Facebook, and Twitter.